A complex junctional system in endothelial and connective tissue cells of the choroid plexus

Endothelial and connective tissue cells of the choroid plexus have been studied by the freeze-etching technique. The endothelial cells of pre- and postcapillary segments are coupled by a complex junctional system consisting of a combination of tight and gap junctions. Connective tissue cells revealed the same intercellular contacts. Furthermore two different types of gap junctions occurring in membranes of the connective tissue cells are described.